1. Field of the Invention
The present invention relates to the field of devices utilized for surface treatment. Treatment of surfaces of material is achieved in many ways, one of which is surface blasting. Surface blasting has unique advantages over other methods of treatment since non-planar surfaces can be effectively treated using blasting by particulate media expelled from a blasting gun at high speed.
Such treatments include surface cleaning such as removing rust from iron or paint from painted surfaces or can be utilized for many other purposes such as modifying surface texture, color, adherence qualities, reflectance or any of a myriad of different properties which a surface may have. Also blasting is commonly used for shot peening to enhance structural strength of treated material.
Such blasting techniques usually utilize particulate blasting materials such as glass beads, etc. The choice of the blasting media is determined by the hardness of the surface and the characteristics of the blasting apparatus. Basically such blasting configurations do fall into two generic categories. The first category is the high pressure blasting systems wherein high pressure air and blasting media are both supplied under high pressure to a blasting nozzle for expelling therefrom and surface treatment by blasting. The second category to which the present invention pertains is suction surface blasting devices. Such devices utilize a high pressure air line supplied to a blasting gun utilized to create a vacuum in a second line extending into the gun such that media is drawn through this second line for mixing with the high pressure air within the gun to impart a high kinetic energy thereto for expelling from the gun for surface blasting. The problems associated with the suction system are completely separate and distinct from those experienced in the design of equipment for high pressure blasting. The present invention deals with the second category or suction surface blasting characteristics utilizing high pressure air and, as such, is deemed to be pneumatic and provides a unique improved media delivery regulating system not shown or suggested in any previous suction blasting apparatus designed heretofore.
2. Description of the Prior Art
Numerous prior art designs have been devised for both high pressure and suction surface blasting such as shown in U.S. Pat. No. 2,114,573 patented Apr. 19, 1938 to G. F. Rhodes on a "Sand Blasting Process"; and U.S. Pat. No. 3,162,986 patented Dec. 29, 1964 to L. Olivieri and assigned to Compagnie de Saint-Gobain on a "Method And Apparatus For Feeding Abrasives"; and U.S. Pat. No. 3,201,901 patented Aug. 24, 1965 to A. M. Pauli on "Abrasive Blasting Equipment"; and U.S. Pat. No. 3,266,193 patented Aug. 16, 1966 to J. D. McCune and assigned to Schlumberger Well Surveying Corporation on a "Sand Supply Container"; and U.S. Pat. No. 3,618,263 patented Nov. 9, 1971 to P. T. weijsenburg and assigned to Atlas Copco Aktiebolag on a "Sandblasting Installation"; and U.S. Pat. No. 3,741,738 patented Jun. 26, 1973 to R. Dowgin and assigned to Pauli & Griffin Co. on "Abrasive Blasting Equipment And Self-Cleaning Abrasive Trap Therefore"; and U.S. Pat. No. 3,768,210 patented Oct. 30, 1973 to C. Johnson et al on an "Automatic Sandblast Machine"; and U.S. Pat. No. 4,048,757 patented Sep. 20, 1977 to J. Kubus et al and assigned to Union Carbide Corporation on a "System For Metering Abrasive Materials"; and U.S. Pat. No. 4,075,789 patented Feb. 28, 1978 to G. Dremann on an "Abrasive System Having A Modulation Function"; and U.S. Pat. No. 4,709,515 patented Dec. 1, 1987 to H. Copeland et al on a "Wet Sandblasting System"; and U.S. Pat. No. 4,854,090 patented Aug. 8, 1989 to R. Heron et al and assigned to The British Hydromechanics Research Association on "Feeding Abrasive Material"; and U.S. Pat. No. 4,959,931 patented Oct. 2, 1990 to R. Howells and assigned to Air Products And Chemicals, Inc. on a "Method And Apparatus For Preventing Binding And Overloading Of Media Feed Screw Conveyor"; and U.S. Pat. No. 5,035,089 patented Jul. 30, 1991 to W. Tillman et al and assigned to Pauli & Griffin on a "Blast Media Recovery And Cleaning System"; and U.S. Pat. No. 5,081,799 patented Jan. 21, 1992 to L. Kirschner et al and assigned to Church & Dwight Co., Inc. on "Blasting Apparatus"; and U.S. Pat. No. 5,083,402 patented Jan. 28, 1992 to L. Kirschner et al and assigned to Church & Dwight Co., Ind. on "Blasting Apparatus"; and U.S. Pat. No. 5,107,630 patented Apr. 28, 1992 to J. Lodewijk and assigned to L.T.C. International B.V. on "Abrasive Blasting Apparatus"; and U.S. Pat. No. 5,123,206 patented Jun. 23, 1992 to J. Woodson and assigned to Whitemetal, Inc. on a "Wet Abrasive Blasting Method"; and U.S. Pat. No. 5,216,848 patented Jun. 8, 1993 to K. Abbott et al and assigned to Stripping Technologies Inc. on "Dual Controls For An Abrasive Blast System"; and U.S. Pat. No. 5,230,185 patented Jul. 27, 1993 to L. Kirschner et al and assigned to Church & Dwight Co., Inc. on a "Blasting Apparatus And Method"; and U.S. Pat. No. 5,325,638 patented Jul. 5, 1994 to W. Lynn on a "Pliant Media Blasting Device"; and U.S. Pat. No. 5,407,379 patented Apr. 18, 1995 to J. Shank et al and assigned to Church & Dwight Co., Inc. on a "Differential Pressure Metering And Dispensing system For Abrasive Media"; and U.S. Pat. No. 5,421,767 patented Jun. 6, 1995 to W. Spears, Jr. et al and assigned to Church & Dwight Co., Inc. on a "Media Control Valve"; and U.S. Pat. No. 5,468,174 patented Nov. 21, 1995 to D. Bachand et al and assigned to IPEC Advanced Systems, Inc. on a "Recyclable Abrasive Blasting System".